The present invention relates in general manner to a power supply unit for supplying an on-board network of a vehicle.
Units for supplying an on-board network of a vehicle with electrical energy existing in the automotive industry include interlaced multi-phase converters working at a fixed frequency (e.g. 150 kHz for each phase). For example, the document FR2970094 describes a unit for supplying electrical energy in an on-board network including a plurality of interlaced converters also working at a fixed frequency.
However, for such a unit, the conducted and radiated emissions are present on a narrow spectrum in radio frequency and filters are thus necessary to meet EMI standards required for the components of a vehicle.
In addition, the converters operating at a fixed frequency do not maintain the stability of the control function for a duty cycle higher than 50% and this limits the output power of the converters and of the unit.
In addition, these interlaced fixed frequency converters, by principle, need to have a minimum duty cycle of minimal control (e.g. 1%) to keep the phase-lock loop stability of the output voltage. This principle involves consuming, at minimum, a load current of a few amperes, which implies poor performance.
In addition, variations in the input voltage of the unit are not taken into account by the regulator of the unit so that the unit operation may become unstable.